The synthesis and utility of pharmacologically active pyridine derivatives and particularly the compound 3-[3-(dimethylamino)propyl]3-(3- methoxyphenyl)-4,4-dimethyl-2,6-piperidinedione, monohydrochloride is described in U.S. Pat. No. 3,963,729, issued Jun. 15, 1976. The compound is useful as an antidepressant. Methods for the preparation of such compounds are disclosed in the patent. In terms of the synthesis of compound 3-[3-(dimethylamino)propyl]-3-(3- methoxyphenyl)-4,4-dimethyl-2,6-piperidinedione, monohydrochloride, the procedure set forth in Scheme I is disclosed. U. S. Pat. No. 4,738,973 discloses use of the compound in treating anxiety and U.S. Pat. No. 4,461,771 discloses its use in treating migraine headaches. ##STR1##